1. Field of the Invention
The present invention relates to processes for preparing optically active 2-aryl cyclohexanols which are important as chiral sources for asymmetric transformations or as chiral materials for asymmetric manufacturing of physiologically active substances such as diltiazem.
2. Description of Related Art
The following prior an references are disclosed in accordance with the terms of CFR 1.56, 1.97, and 1.98.
U.S. Pat. No. 4,871,855 (Oct. 3, 1989) discloses an asymmetric dihydroxylation of a wide variety of olefins.
U.S. Pat. No. 4,965,364 (Oct. 23, 1990) discloses an asymmetric dihydroxylation of a wide variety of olefins.
U.S. Pat. No. 5,002,776 (Mar. 26, 1991) discloses controlled absorption pharmaceutical formulations containing diltiazem.
U.S. Pat. No. 5,008,411 (Apr. 16, 1991) discloses a process of preparing (-)-(1R,2S)-2-phenylcyclohexanol from (+)-trans-2-phenylcyclohexanol chloroacetate using a lipase from pseudonomas fluoresens.
U.S. Pat. No. 5,126,494 (Jun. 30, 1992) discloses methods for catalytic asymmetric dihydroxylation of olefins.
Japanese patent application 5246918 (Sep. 24, 1993) discloses optically active trans-2-arylcyclohexanol derivatives prepared by ester exchange between 2-aryl-1-cyclohexanol and fatty acid, vinyl esters, or triglycerides in the presence of esterase.
Organic Synthesis, 1990, volume 69, page 1 discloses a process for preparing phenyl cyclohexanol from cyclohexene oxide and phenylmagnesium bromide using a step which employs Lipase.
Tetrahedron Asymmetry, 1992, 3, 1029 discloses asymmetric hydrosilylation of 2-phenylcyclohexanone.
All of the above-cited prior an patents and articles are incorporated herein by reference in their entirety.